Control apparatus for swing type hydraulic shovel

Abstract

 The invention provides a control apparatus for a swing type hydraulic shovel which can carry out a stable hanging work. The apparatus is provided with a mode switching means (33) capable of selecting a hanging work mode, a swing detector (20) for detecting whether or not a working implement (5) is in a swing state, an alarm means (30) for receiving an alarm command from an external portion and generating an alarm, and a controller (32) for judging on a detection signal of the swing detector (20) whether or not the working implement (5) is in a swing state, at a time when a selection command of a hanging work mode is input from the mode switching means (33), and outputting to the alarm means (30) a command that the hanging work mode is not started, if it is in the swing state.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to an apparatus for controlling an interlock between a swing motion and a hanging work in a swing type hydraulic shovel capable of carrying out a hanging work by using a swing type boom.

BACKGROUND OF THE INVENTION

[0002] In conventional, for example, as shown in Figs. 1 and 2, there has been widely known a swing type hydraulic excavator (hereinafter, refer to as a hydraulic shovel) which is provided with a working implement 5 having a boom 12, an arm 14 and a bucket 6 swingably connected to each other within a vertical surface, in a front portion of an upper revolving body 1 mounted in an upper portion of a lower traveling body 2 so as to freely revolve, and has a structure in which the working implement 5 is attached to the upper revolving body 1 via a bracket 21 so as to freely oscillate (hereinafter, refer to as swing) in a lateral direction within a horizontal surface around a pin 23. A counterweight 7 for balancing with the working implement 5 is mounted to a rear end portion of the upper revolving body 1.

[0003] The swing type hydraulic shovel of this type can carry out a normal excavating work of excavating sediments or the like by the bucket 6, in a neutral state 5a (refer to Fig. 2) in which the working implement 5 is set straight in a forward direction of the upper revolving body 1. Further, a side groove excavation in right and left sides of the vehicle can be carried out by swinging the working implement 5 in an opposite direction to the revolution from the neutral state 5a, at a position where the upper revolving body 1 is turned at a predetermined angle from a position directed to a forward side of the vehicle. These works are generically called as an excavating work.

[0004] In recent years, in order to correspond to a diversification of the work, there is a desire of a swing type hydraulic shovel which can carry out a hanging work for handing a load to the working implement 5. For example, as shown in a detailed view of a bucket attachment portion in Fig. 3, there is a structure in which a base end portion of a hook 27 is rotatably attached to a connection pin 29 connecting a front link 28 provided between the bucket 6 and an arm 14 and transmitting a swing driving force to the bucket 6 to the bucket 6. In this case, the slinging load is hanged to the hook 27 and a hanging work for hanging the load can be carried out by rising up the boom 12 and/or the arm 14.

[0005] However, in the swing type hydraulic shovel capable of carrying out the hanging work, the hanging work can be carried out in a most stable manner, at a position where the working implement 5 is best balanced with the counter weight 7 in view of a weight balance, that is, the working implement 5 is in a neutral state 5a with respect to the upper revolving body 1. On the contrary, when the hanging work is carried out in a state in which the working implement 5 is swung rightward or leftward from the neutral state 5a, or when the working implement 5 is swung during the hanging work in the neutral state 5a, it becomes hard to balance the swing type hydraulic shovel, so that a stability of the swing type hydraulic shovel is reduced, and the hanging load tends to swing.

[0006] However, there is a case that an operator erroneously carries out the hanging work without being strongly aware of this matter. In the conventional swing type hydraulic shovel, in the case that the operator swings the working implement 5 from the neutral state 5a during the hanging work, or carries out the hanging work in the state of swinging the working implement 5 from the neutral state 5a, there is no way for informing the operator of the fact that the vehicle becomes unstable due to the work. Since the operator keeps the hanging work as it is, the vehicle becomes unstable and the hanging load swings. Accordingly, there is generated a problem that a working efficiency is reduced, the hanging load is in contact with an external portion, and the like.

SUMMARY OF THE INVENTION

[0007] The present invention is made by taking the problem mentioned above into consideration, and an object of the present invention is to provide a control apparatus for a swing type hydraulic shovel which can carry out a stable hanging work.

[0008] In accordance with a first aspect of the present invention, there is provided a control apparatus for a swing type hydraulic shovel in which a working implement is mounted to an upper revolving body so as to freely swing in a lateral direction, compres a mode switching means for outputting a selection command of a hanging work mode which is preferable for a hanging work hanging a load by the working implement, a swing detector for detecting whether the working implement is in a neutral state in which the working implement is directed to a forward side of the upper revolving body or the working implement is in a swing state in which the working implement swings from the neutral state, an alarm means receiving an alarm command from an external portion and generating an alarm by way of at least one of an alarm display and an alarm sound, and a controller judging on the basis of the detection signal of the swing detector whether or not the working implement is in the swing state, at a time when the selection command of the hanging work mode is input from the mode switching means, and outputting to the alarm means an alarm command reporting the matter the hanging work mode is not set, if the working implement is in the swing state.

[0009] In accordance with the first aspect, in the case that the working implement is in the swing state even when the hanging work mode is selected by the mode switching means, the hanging work mode is not set, and the alarm means reports through the display of the alarm or the alarm sound that the hanging work mode is not set (the swing state is set). Accordingly, the operator can immediately know this state, and can appeal to the operator that the alarm state should be canceled. Since the operator is encouraged that the working implement should be returned back to the neutral state from the swing state and the hanging work should be carried out, it is possible to carry out the hanging work in a stable state.

[0010] In accordance with a second aspect of the present invention, there is provided a control apparatus for a swing type hydraulic shovel in which a working implement is mounted to an upper revolving body so as to freely swing in a lateral direction, comprises a mode switching means for outputting a selection command of a hanging work mode which is preferable for a hanging work hanging a load by the working implement, a swing detector for detecting whether the working implement is in a neutral state in which the working implement is directed to a forward side of the upper revolving body or the working implement is in a swing state in which the working implement swings from the neutral state, an alarm means receiving an alarm command from an external portion and generating an alarm by way of at least one of an alarm display and an alarm sound, and a controller monitoring on the basis of the detection signal of the swing detector whether or not the working implement is in the swing state, at a time when the hanging work mode is set on the basis of the selection command of the hanging work mode output from the mode switching means, and outputting to the alarm means an alarm command reporting the matter the working implement is under swinging, in the case that the working implement becomes in the swing state.

[0011] In accordance with the second aspect, in the case that the working implement is in the swing state at a time when the hanging work mode is set, the matter that the working implement is under swinging is reported through the display of the alarm or the alarm sound of the alarm means. Accordingly, the operator can immediately know this state, and can appeal to the operator that the alarm state should be canceled. Thus, since the operator is encouraged that the working implement should be returned back to the neutral state from the swing state and the hanging work should be carried out, it is possible to carry out the hanging work in a stable state.

[0012] In accordance with a third aspect of the present invention, there is provided a control apparatus for a swing type hydraulic shovel as recited in the first aspect or the second aspect, wherein the swing detector is a limit switch which turns on or off in correspondence to the swing of the working implement and detects whether or not the working implement exists within a predetermined range indicating the neutral state.

[0013] In accordance with the third aspect, since it is detected by the limit switch whether or not the working implement is in the neutral state or the swing state, it is possible to securely detect the state by a simple structure with a low cost.

[0014] In accordance with a fourth aspect of the present invention, there is provided a control apparatus for a swing type hydraulic shovel as recited in the first aspect or the second aspect, wherein the swing detector is a detector for detecting a stroke length of a swing cylinder swinging the working implement in equivalent to a swing angle of the working implement.

[0015] In accordance with the fourth aspect, it is possible to detect whether or not the working implement is in the neutral state or the swing state, by detecting the stroke length of the swing cylinder in correspondence to the swing angle of the working implement. Since the judgment can be carried out by optionally setting a predetermined swing angle range indicating the neutral state in correspondence to an applied machine, the present control apparatus can be applied to no particular kinds of machines and it is possible to further increase a general-purpose property.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 

Fig. 1 is a side elevational view of a swing type hydraulic shovel to which the present invention is applied;

Fig. 2 is a plan view of a main portion in accordance with a first embodiment of the present invention;

Fig. 3 is a detailed view of a bucket attachment portion to which the present invention is applied;

Fig. 4 is a block diagram of a hard ware structure of a control apparatus in accordance with the first embodiment;

Fig. 5 is a perspective view of a monitor apparatus in accordance with the first embodiment;

Fig. 6 is a flow chart of a control in accordance with the first embodiment;

Fig. 7 is a perspective view of a mounting portion of a swing detector in accordance with a second embodiment; and

Fig. 8 is a perspective view of a swing detector in accordance with a third embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

[0017] A description will be in detail given below of embodiments in accordance with the present invention with reference to the accompanying drawings. First, a description will be given of a first embodiment with reference to Figs. 1 to 6.

[0018] Fig. 1 is a side elevational view of a swing type hydraulic shovel to which the present invention is applied, and Fig. 2 is a plan view of a main portion thereof. In Figs. 1 and 2, the swing type hydraulic shovel has a lower traveling body 2, an upper revolving body 1 provided in an upper portion of the lower traveling body 2, and a working implement 5 provided in a front portion of the upper revolving body 1. In the following description, a traveling direction of a hydraulic shovel shown by an arrow F (front) - R (rear) in Fig. 1 is called as a longitudinal direction, and a vehicle width direction orthogonal to the longitudinal direction is called as a lateral direction.

[0019] The lower traveling body 2 is provided with a pair of right and left crawler type traveling apparatuses 4, and a travel driving portion 11 for driving the traveling apparatus 4 by a hydraulic motor is provided in one side in the longitudinal direction of each of the crawler type traveling apparatuses 4. The upper revolving body 1 is mounted on an approximately center upper portion of the lower traveling body 2 so as to freely revolve, and the working implement 5 is provided in an approximately center of a front portion f the upper revolving body 1.

[0020] A bracket 21 is connected to a working implement mounting portion 24 provided in a front end portion of the upper revolving body 1 by a pin 23 (refer to Fig. 2) so as to freely swing in the lateral direction within a horizontal surface. The bracket 21 swings in the lateral direction around the pin 23 on the basis of a telescopic motion of a swing cylinder 22 attached between the bracket 21 and the upper revolving body 1. Further, a base end portion of a boom 12 is connected to a leading end portion of the bracket 21 so as to freely swing in the vertical direction, a base end portion of an arm 14 is connected to a leading end portion of the boom 12 so as to freely swing in the longitudinal direction, and the bucket 6 is connected to a leading end portion of the arm 14. The boom 12, the arm 14 and the bucket 6 respectively swing on the basis of telescopic motions of a boom cylinder 13, an arm cylinder 15 and a bucket cylinder 17. The working implement 5 is constructed by these elements. In the following description, a lateral swing angle from a neutral state 5a of the working implement 5 in a plan view is called as a swing angle θ, and a motion of contracting the bucket cylinder 17 so as to swing the bucket 6 forward is called as a dump motion.

[0021] In this case, a projection portion 25 is provided in a rear portion of the bracket 21 in a protruding manner. A limit switch 26 is mounted to a frame in a side of the upper revolving body 1 close to the projection portion 25 at a time when the bracket 21 is at a neutral position directed to a forward side of the vehicle. The limit switch 26 is provided so that an operation piece 26a of the limit switch 26 is pressed down by the projection portion 25 so as to operate, at a time when the bracket 21 is at the neutral position. The limit switch 26 detects that the operation of the operation piece 26a is turned off and the operation piece 26a is swung from the portion close to the neutral position, if the bracket 21 swings at a predetermined angle (for example, ± 5 degrees) or more in the lateral direction from the neutral position, and the limit switch 26 transmits the detection signal to a controller mentioned below. In the following description, a state in which the bracket 21, that is, the boom 12 swings at the predetermined angle or more from the neutral position is called as under swing or a swing state.

[0022] Fig. 3 shows details of a bucket attachment portion. As shown in Fig. 3, a base end portion of a hook 27 is pivoted to a pin 29 which connects the bucket 6 to a front link 28 transmitting a driving force of the bucket cylinder 17 to the bucket 6 so as to swing the bucket 6 (this structure is not illustrated in Figs. 1 and 2).

[0023] Fig. 4 shows a block diagram of a hard ware structure of the control apparatus for the swing type hydraulic shovel in accordance with the present invention. The present control apparatus is provided with a controller 32 for carrying out an automatic control of a hanging work, a swing detector 20 for detecting that the working implement 5 is in the neutral state, a monitor apparatus 30 having a display device 34 for displaying an operation state and an alarm message, and a mode switch 33, a rotation alarm lamp 31, a first solenoid valve 35 for driving a swing motion of the bucket 6, a second solenoid valve 36 for carrying out a speed increase and a speed decrease of the travel driving portions 11 and 11, and a motor 37 for carrying out a rotational speed control of the engine. All of the swing detector 20, the monitor apparatus 30, the rotation alarm lamp 31, the solenoid valves 35 and 36 and the motor 37 are electrically connected to the controller 32. The swing detector 20 has the limit switch 26 in the present embodiment.

[0024] The controller 32 is mainly constituted by a high speed processor such as a micro computer or the like, carries out a control process mentioned below on the basis of a detection signal of the swing detector 20, and executes various kinds of hanging work automatic control or hanging work alarm process or the like.

[0025] The rotation alarm lamp 31 is structured such that the lamp is rotated and turned on in accordance with the command output from the controller 32 during the hanging work automatic control so as to report to an operator or the like that the hanging work is under an automatic control. This rotation alarm lamp 31 is placed at a position in front of a driver seat where the operator can easily view, for example, a portion close to the monitor apparatus 30 shown in Fig. 5.

[0026] The first solenoid valve 35 drives the telescopic motion of the bucket cylinder 17 on the basis of the command output from the controller 32, thereby carrying out a dump motion (a forward swing motion) of the bucket 6 or a scooping motion. Further, the second solenoid 36 controls a flow rate, that is, a rotational speed of the hydraulic motor in the travel driving portions 11 and 11, on the basis of the command output from the controller 32, thereby increasing or decreasing the speed of the traveling apparatus 4 in correspondence to a speed stage.

[0027] Further, the motor 37 is controlled in an angle of rotation on the basis of the command output from the controller 32, thereby controlling an angle of swing of an engine throttle lever (not shown) connected to an output shaft of the motor 37, that is, an engine speed.

[0028] The monitor apparatus 30 shown in Fig. 5 is provided with a display device 34 for displaying an operation state and an alarm message, and a mode switch 33 switching a work mode such as a hanging work mode, an excavating work mode or the like so as to set, and serving as a mode switching means. The monitor apparatus 30 displays an operation state, an alarm message or the like on the display device 34 in accordance with the command output from the controller 32, and can switch the work mode between the excavating work mode at a time of carrying out the excavating work and the hanging work mode at a time of carrying out the hanging work, in accordance with the operation of the mode switch 33 by the operator.

[0029] In this case, the display device 34 is constituted by a character display device or a graphic display device capable of displaying a message and comprising a liquid crystal display device, a plasma display device or the like, or an LED display device capable of displaying an alarm code (alphameric characters and the like). Further, the mode switch 33 is constructed by a momentary type switch (for example, a touch switch or a push button switch). In this case, the monitor apparatus 30 may have the display device 34 carrying out an alarm display, a buzzer generating an alarm sound or both of them, as an alarm means.

[0030] A description will be given below of an operation in the case that the hanging work is carried out in the swing type hydraulic shovel.

[0031] It is supposed that when turning on a key switch (not shown), the controller 32 is set to the excavating work mode as an initial state. In the case of carrying out the hanging work, the operator operates the mode switch 33 of the monitor apparatus 30 and selects the hanging work mode. At this time, when the working implement 5 is in the neutral state 5a, the controller 2 starts the hanging mode.

[0032] In the hanging work mode, the controller 32 carries out the following hanging work automatic control.

(a) Carrying out an arithmetical operation of the hanging load weight, carrying out a comparison between the arithmetically operated load weight value and a maximum allowed value, and carrying out an alarm display on the display device 34 of the monitor apparatus 30 in the case that the hanging load weight is over the maximum allowed value.

(b) Displaying the load weight value during the hanging work on the display device 34 of the monitor apparatus 30.

(c) Turning on the rotation alarm lamp 31 during the automatic control of the hanging work.

(d) Controlling the first solenoid valve 35 and inhibiting the dump motion of the bucket 6 (the forward swing motion).

(e) Controlling the second solenoid valve 36 and limiting the rotational speed so that the rotational speed of the hydraulic motor in the travel driving portion 11 is not over a range of a first speed (a low speed range).

(f) Controlling the motor 37, and limiting the engine speed so that the engine speed is not over a predetermined upper limit value.

[0033] By carrying out these controls, the operator can easily know the hanging load weight and the state of the load alarm at a time of the hanging work, and an attention is drawn at a time of hanging the load having an excessive weight equal to or more than the allowed value. Further, since the motion which makes the hanging state unstable (the load is oscillated) such as the dump motion, the increase of the traveling speed, the increase of the working implement or the like is limited during the hanging work, a stable hanging work can be maintained. In principle, the hanging work is carried out in the neutral state in which the boom 12 is not swung.

[0034] Next, a description will be given of a case that it is intended to carry out the hanging work in a state in which the operator swings the boom 12 at a predetermined angle or more from the neutral position, at a time when the work mode is set to the excavating work mode. When carrying out the hanging work in a state in which the boom 12 is swung from the neutral position, a stability of the vehicle body in the swing type hydraulic shovel is reduced, and the load is swung. In order to prevent this, the controller 32 controls so that the hanging work mode is not started in a state in which the boom 12 is swung from the neutral position, even when the operator operates the mode switch 33 so as to achieve the hanging work mode.

[0035] Fig. 6 shows a control procedure of the controller 32 in the case that the operator operates the mode switch 33 so as to switch the mode from the excavating work mode to the hanging work mode, on the basis of a flow chart.

[0036] When the hanging work mode is selected (a step S1), the controller 32 first judges on the basis of the output of the limit switch 26 whether or not the boom 12 is in the state in which the boom 12 is swung rightward or leftward from a predetermined range including the neutral position (a step S2). If the mode is not under swinging in the step S2, the hanging work mode is started, and the hanging work automatic control mentioned in the items (a) to (f) mentioned above is executed (a step S4). If the mode is under swinging in the step S2, the excavating work mode is continued, and the alarm message, for example, "under swinging" or the like is displayed on the display device 34 of the monitor apparatus 30 (a step S3). At this time, the alarm buzzer may be ringed. The judgement whether or not the mode is under swinging is carried out on the basis of the signal of the limit switch 26 as mentioned above, and in the case that the boom 12 is in the range within the predetermined angle (± 5 degrees) from the neutral state, it is judged that the mode is not under swinging. In this flow chart, whether or not the load is actually hanged in the working implement 5 is no object.

[0037] Accordingly, even when the operator intends to set the hanging work mode in the swing state, the rotation alarm lamp 31 is not turned on, the load amount value is not displayed on the monitor apparatus 30, and the alarm message is displayed. Therefore, the operator becomes aware of the matter that the hanging work mode is not immediately started. Thereafter, a stable hanging work can be carried out by returning the boom 12 to the neutral state from the swing state and again carrying out the hanging work.

[0038] Next, a description will be given of a case that the operator intends to carry out the swing motion after the hanging work mode is started in the step S4, in this flow chart. In this case, the controller 32 is structured such as to inform the operator of swinging in the hanging work mode.

[0039] In Fig. 6, if the hanging work mode is started in the step S4, the controller 32 monitors on the basis of the signal of the limit switch 26 whether or not the boom 12 is in the swing state (a step S5). Further, when it is judged that the swing state is started, the load amount value display on the display device 34 of the monitor apparatus 30 is stopped in the hanging work automatic control (b), and the alarm message indicating the swing motion is carried out is displayed on the display device 34 (a step S6), and the step next goes to a step S7. In this case, the alarm buzzer may be ringed at this time. In the case that the swing state is not carried out in the step S5, the step goes to the step S7, and it is judged in the step S7 whether or not the excavating work mode is selected by the mode selecting switch 33. If the excavating work mode is not selected, the step goes back to the step S4 and the above processes are repeated, and if the excavating work mode is selected, the excavating work mode is started (a step S8) and the step goes back to the step S1.

[0040] Accordingly, even when the operator intends to swing the boom 12 under the hanging work mode erroneously, the load amount value is not displayed on the monitor apparatus 30, the alarm message is displayed, and the alarm buzzer is ringed. Therefore, the operator becomes aware of the matter that the swing motion is carried out during the hanging work immediately, and an attention is drawn. Then, the operator returns the boom 12 from the swing state to the non-sing state (the neutral state), and intends to carry out a stable hanging work.

[0041] In accordance with the first embodiment, the limit switch 26 is provided as the swing detector 20 for detecting whether or not the boom 12 is swung from the neutral state. Accordingly, it is possible to inexpensively and securely detect the swing state of the boom 12 in accordance with a simple structure. In this case, in place of the mechanical limit switch 26, a non-contact type detector, for example, a magnetic type contactless switch or the like may be used as the swing detector 20.

[0042] Then, if the swing state is carried out at a time when the mode switch 33 is operated so that the mode is changed from the excavating work mode to the hanging work mode, on the basis of the judgement of the swing state, the mode is not changed to the hanging work mode. Accordingly, since the hanging work automatic control in the items (a) to (f) is not carried out, the rotation alarm lamp 31 is not turned on, the load amount value is not displayed on the monitor apparatus 30, and the alarm message is displayed, the operator can immediately and easily know that the hanging work mode is selected during the swing motion of the boom 12, and an attention is drawn. Further, a stable hanging work can be carried out by returning the mode to the non-swing state and again starting the hanging work mode.

[0043] Further, when the hanging work mode is carried out, it is always monitored whether or not the swing state is started. Then, in the case that the swing motion deflecting from the neutral state is carried out, the alarm informing of the matter is generated by displaying the matter on the monitor apparatus 30 and/or alarming by the buzzer or the like, so that the operator can immediately and easily know that the boom 12 becomes in the swing state, and an attention is drawn. In this case, since the other hanging work automatic control than displaying the alarm message in place of the load amount value on the display device 34 of the monitor apparatus 30 is executed, it is possible to prevent the unstable state from being generated without interrupting the automatic control in the middle of the hanging work. Further, the stable hanging work can be carried out by continuing the hanging work after returning the boom 12 in the non-swing state.

[0044] Next, a description will be given of a second embodiment with reference to Fig. 7. A hard ware structure of a control apparatus in accordance with the second embodiment is the same as that shown in Fig. 4, and a description will be given of the swing detector 20 for detecting a swing state of a working implement which is different from the first embodiment.

[0045] Fig. 7 is a perspective view of a base end portion of a boom 12 in a swing type hydraulic shovel in accordance with the second embodiment, and shows a mounting portion of the swing detector 20. There is shown a state in which the upper revolving body 1, the bracket 21 and the boom 12 are separated from each other.

[0046] In Fig. 7, as the swing detector 20, a potentiometer 41 for detecting a swing angle θ of the boom 12 is provided on an axis of the pin 23 which swingably connects the working implement mounting portion 24 of the upper revolving body 1 to the bracket 21.

[0047] The potentiometer 41 is connected to a pin 43 mounted to an upper portion of the working implement mounting portion 24 by a connection member 42. Accordingly, it is possible to accurately detect an angle within a horizontal surface of the bracket 21 with respect to the working implement mounting portion 24, that is, the swing angle θ of the boom 12. The detection angle is input to the controller 32, and the controller 32 can judge on the basis of the detection angle whether the swing state (swinging at a predetermined angle or more from the neutral position) or the non-swing state (within the predetermined angle from the neutral position).

[0048] Further, the judgement whether the swing state or the non-swing state can be carried out on the basis of a suitable angle range in correspondence to an applied machine, for example, ± 6 degrees and ± 10 degrees, without being limited to the predetermined angle ± 5 degrees. Further, the operator can easily return the working implement 5 to the neutral position by displaying the swing angle θ, in addition to the result of judgement whether or not the swing state is carried out, for example, on the monitor apparatus 30.

[0049] Next, a description will be given of a third embodiment with reference to Fig. 8. A hard ware structure of a control apparatus in accordance with the third embodiment is also the same as the structure shown in Fig. 4, and a description will be given of a swing detector 20 which is different from the first and second embodiments.

[0050] In Fig. 8, a swing type hydraulic shovel has a detector for detecting a stroke length of the swing cylinder 22 as the swing detector 20. A reel 44 energized in a wire take-up direction is mounted to an outer portion of a tube in the swing cylinder 22, a wire mounting portion 40 is provided in a leading end portion of a piston in the swing cylinder 22 connected to the bracket 21, a wire 38 is extended between the wire mounting portion 40 and the reel 44 so as to be freely taken up, and an encoder 39 for detecting an angle of rotation of the reel 44 is provided. Further, a feeding amount of the wire 38, that is, a stroke length of the swing cylinder 22 is detected as an angle of rotation of the reel 44 by the encoder 39, and this detection signal is input to the controller 32.

[0051] The stroke length of the swing cylinder 22 can be converted into the swing angle θ on the basis of a relational expression determined by a mechanical structure obtained by a relation between a mounting position of the end portion of the tube in the swing cylinder 22 and a position of a swing center (the pin 23) of the bracket 21, a relation between a position of the wire mounting portion 40 in the leading end portion of the piston and a position of the swing center of the bracket 21, and the like. In this case, the swing angle θ may be determined in accordance with a corresponding data table between the stroke length of the swing cylinder 22 and the swing angle θ, which is determined on the basis of the relational expression obtained in accordance with the mechanical structure.

[0052] In accordance with the present embodiment, since the swing angle θ is equivalently detected by the encoder 39, it is possible to easily set and judge the range indicating the neutral state of the working implement 5 in correspondence to the applied machine, in the same manner as that of the second embodiment. Therefore, it is possible to widen the range to which the present control apparatus is applied. In this case, the hydraulic shovel having the crawler type traveling apparatus is shown as the example to which the present invention is applied, however, the applied machine is not limited to this, for example, a tire wheel type may be employed.

[0053] As described above, in accordance with the present invention, the following effects can be obtained.

[0054] In order to stably carry out the hanging work, in the swing type hydraulic shovel which can select the hanging work mode in which the hanging work is automatically controlled by adding various kinds of auxiliary functions, when the swing state of the working implement and the hanging work mode mentioned above simultaneously occur, the matter that the working implement is in the swing state is informed to the operator by the alarm means.

[0055] In the case that the hanging work mode is selected in the swing state, or in the case that the swing state is set in the hanging work mode, the matter that the working implement is in the swing state is informed to the operator, by the alarm display and/or the buzzer alarm sound. Accordingly, the operator can immediately and easily know that the alarm state is generated, and an attention is drawn to the operator, so that it is easily carried out the operation of returning the working implement to the neutral state and canceling the alarm state. Therefore, it is possible to carry out the hanging work in the state in which the vehicle body is in the stable state.

[0056] At this time, in the case that the limit switch is used as the swing detector for detecting the swing state of the working implement, the present Apparatus can be inexpensively constructed on the basis of the simple structure. Further, since the swing angle is detected by the angle around the center axis of swing of the working implement or the stroke length of the swing cylinder, it is possible to easily correspond to the matter only by changing the judgment reference data, even when the detection range of the swing state is set to the range matching to the applied machine. Accordingly, it is possible to further increase a general-purpose property of the present control apparatus.

Claims

1. A control apparatus for a swing type hydraulic shovel in which a working implement (5) is mounted to an upper revolving body (1) so as to freely swing in a lateral direction, comprising:

a mode switching means (33) for outputting a selection command of a hanging work mode which is preferable for a hanging work hanging a load by the working implement;

a swing detector (20) for detecting whether the working implement is in a neutral state (5a) in which the working implement is directed to a forward side of said upper revolving body or the working implement is in a swing states in which the working implement swings from the neutral state;

an alarm means (30) receiving an alarm command from an external portion and generating an alarm by way of at least one of an alarm display and an alarm sound; and

a controller (32) judging on the basis of the detection signal of said swing detector whether or not the working implement is in the swing state, at a time when the selection command of the hanging work mode is input from said mode switching means, and outputting to said alarm means an alarm command reporting the matter the hanging work mode is not set, if the working implement is in the swing state.

2. A control apparatus for a swing type hydraulic shovel in which a working implement (5) is mounted to an upper revolving body (1) so as to freely swing in a lateral direction, comprising:

a mode switching means (33) for outputting a selection command of a hanging work mode which is preferable for a hanging work hanging a load by the working implement;

a swing detector (20) for detecting whether the working implement is in a neutral state (5a) in which the working implement is directed to a forward side of said upper revolving body or the working implement is in a swing state in which the working implement swings from the neutral state;

an alarm means (30) receiving an alarm command from an external portion and generating an alarm by way of at least one of an alarm display and an alarm sound; and

a controller (32) monitoring on the basis of the detection signal of said swing detector whether or not the working implement is in the swing state, at a time when the hanging work mode is set on the basis of the selection command of the hanging work mode output from said mode switching means, and outputting to said alarm means an alarm command reporting the matter the working implement is under swinging, in the case that the working implement becomes in the swing state.

3. A control apparatus for a swing type hydraulic shovel as claimed in claim 1 or 2, wherein said swing detector (20) is a limit switch (26) which turns on or off in correspondence to the swing of said working implement (5) and detects whether or not the working implement exists within a predetermined range indicating the neutral state.

4. A control apparatus for a swing type hydraulic shovel as claimed in claim 1 or 2, wherein said swing detector (20) is a detector (39) for detecting a stroke length of a swing cylinder (22) swinging the working implement in equivalent to a swing angle (θ) of said working implement.

Drawing